Haim, who was 38 and had long battled drugs, was found by his mother, unconscious in her apartment, according to People magazine. The L.A. coroner's office said Haim died at 2:15 a.m. at Providence St. Joseph Medical center in Burbank.
"It was an apparent overdose," LAPD Sgt. Frank Albarren said. "Unknown what type of medication."
L.A. Coroner Ed Winter said four bottles of prescription pills were found in the home, in the Oakwood Apartments, and there were no "illicit drugs" or signs of suicide. Winter also said Haim had suffered flu-like symptoms for several days, but declined to speculate on the exact cause of Haim's death. He said Haim's mother found him unresponsive after he got out of bed and collapsed.
Haim, who was born in 1971 in Ontario, Canada, broke into acting with a role on a TV series in his native country in 1982. From there, he went on to film work, appearing in 1984's "Firstborn," with Sarah Jessica Parker and Robert Downey Jr. Throughout the 1980s, he was seen in several major movies, including "The Lost Boys," with Kiefer Sutherland.
But the adult success that came to so many of Haim's co-stars eluded him and his life spiraled to the point he was paired in 2007 with another troubled child actor, Corey Feldman, in an A&E reality show called "The Two Coreys." The show was somewhat successful, though it drew heavily on the depressing status of two onetime stars unable to recapture their past glory.
Haim continued to make movies in the 1990s, but most were direct-to-video flops and ill-conceived sequels of earlier hits. He filed for bankruptcy in 1997, and in the ensuing years, became addicted to crack, suffered a stroke and tried drug rehab 15 times by his own count.
"I was working on The Lost Boys (1987) when I smoked my first joint. But a year before that, I was starting to drink beer on the set of the film Lucas (1986). I lived in Los Angeles in the '80s, which was not the best place to be. I did cocaine for about a year and a half, then it led to crack.
"I started on the downers which were a hell of a lot better than the uppers because I was a nervous wreck," Haim told The Sun in 2004. "But one led to two, two led to four, four led to eight, until at the end it was about 85 a day — the doctors could not believe I was taking that much. And that was just the Valium — I’m not talking about the other pills I went through."
The fascination with Haim's tragic, three-decade plunge, which was punctuated by failed comebacks, was summed up by The Thrills" 2004 hit song, "Whatever Happened to Corey Haim?"
In an interview shortly after the song came out, Haim attempted to answer the question. "I want people to listen to the song and know I'm clean, sober, humble and happy."
But the show he starred on with Feldman years later collapsed in part because Feldman refused to speak to him until he got sober.
"I don’t feel that he's a safe person to have around my wife and child at the moment, for a multitude of reasons," Feldman told People in 2008.
Today, Feldman expressed his grief over Haim's death, whom he called his "brother."
"I was awakened at 8:30 this morning by my brother and sister knocking on my bedroom door," Feldman said in a statement to Access Hollywood. "They informed me of the loss of my brother Corey Haim. My eyes weren't even open all the way when the tears started streaming down my face.
"I am so sorry for Corey, his mother Judy, his family, my family, all of our fans, and of course my son who I will have to find a way to explain this to when he gets home from school," he continued. "This is a tragic loss of a wonderful, beautiful, tormented soul, who will always be my brother, family, and best friend. We must all take this as a lesson in how we treat the people we share this world with while they are still here to make a difference. Please respect our families as we struggle and grieve through this difficult time. I hope the art Corey has left behind will be remembered as the passion of that for which he truly lived."